Check sibling questions

Ex 13.2, 9 - Chapter 15 Class 11 Statistics (Important Question)

Last updated at May 26, 2023 by

Ex 15.2, 9 - Find mean, variance, standard deviation using short - Standard deviation and variance - Continuous frequency (grouped data)

Ex 15.2, 9 - Chapter 15 Class 11 Statistics - Part 2
Ex 15.2, 9 - Chapter 15 Class 11 Statistics - Part 3

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class

Book a free demo

Transcript

Ex15.2, 9 Find the mean, variance and standard deviation using short-cut method Mean(π‘₯ Μ…) = A + (βˆ‘β–’π‘“π‘–π‘¦π‘–)/(βˆ‘β–’π‘“π‘–) Γ—β„Ž where A = assumed mean = 92.5 𝑦_𝑖=(π‘₯_𝑖 βˆ’ 𝐴)/β„Ž h = class size = 75 βˆ’ 70 = 5 Variance (𝜎)2 = β„Ž2/N2 [π‘βˆ‘β–’π‘“π‘–π‘¦π‘–2 βˆ’ (βˆ‘β–’π‘“π‘–π‘¦π‘–)^2 ] = 52/602 [N Γ— (254) – (6)2] = 25/3600 [60 Γ—254 βˆ’36] = 25/3600 Γ— 15204 = 105.58 ∴ Standard deviation (𝜎) = √Variance = √105.58 = 10.27

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.